Isolation and culture in artificial media of Lagenidium from Penaeus monodon larvae

Fungal infection of P. monodon larvae is a problem in hatchery operations. The fungus, which attacks the nauplius to postlarval stages and causes up to 100% mortality, has been tentatively identified as belonging to the genus Lagenidium . This pathogenic organism has recently been isolated and cultured. A description is given of the fungus, and features of its biology and pathology are discussed.

Improvement in quality and shelf-life of whole dried prawns

A simple and effective method is suggested to improve the quality and shelf-life of commercial whole dried thelly prawns (Metapenaeus dobsoni). Treatment of whole prawns in 10% brine containing 0.1% citric acid for 20 min followed by drying in sun yield a product having good physical, chemical and organoleptic characteristics. Retardation of fungal incidence, reduction in total volatile nitrogen (TVBN) and improvement in flavour are some of the advantages of the treatment. The treated product has a shelf-life around 30 weeks compared to 20 weeks for untreated control and 7 weeks for commercial sample.

Health status of a snakehead (Channa punctatus) of two fish markets in Mymensingh, Bangladesh

An experiment was carried out for a period of six months during October 2008 to March 2009 to investigate the health status of a snakehead, Channa punctatus through clinical and histopathological technique. Fish were collected from two fish markets of Mymensingh district. Clinically and histopathologically, it was observed that fishes from both the markets were healthy in October and March but moderately affected in November and February. In the months of December and January, 7.5- 8% of the fishes were affected clinically and showing various clinical signs like, discolouration, deep ulcer, ill health, scale loss and rough skin. Histopathologically, in the month of December and January, major observed pathologies of skin and muscle were necrosis, vacuums, fungal granuloma and loss of dermis. Gills were affected having parasitic cysts, monogenetic trematode, clubbing, loss of primary and secondary gill lamellae, hemorrhage, necrosis and hypertrophy. Vacuoles, pyknosis, hepatic necrosis, hemorrhages and fungal granuloma were observed in liver. Renal pathology included necrosis and pyknosis of kidney tubules, hemorrhages, presence of bacterial colony and vacuoles. From present findings, it was found that, fishes from urban market were more affected with diseases than pre-urban market especially in the months of December and January when compared with other months. From overall observation, C. punctatus were severely affected by epizootic ulcerative syndrome (EUS), dactylogyrosis, protozoan and bacterial diseases during colder months of the year.